feat: implement SSE real-time frontend updates on new payload reception

backend/index.js

@@ -143,6 +143,12 @@ app.post('/api/data', authenticateAPIKey, async (req, res) => {
             }
             
             await client.query('COMMIT');
+            
+            // Broadcast update to all connected SSE clients
+            const broadcastMessage = `data: {"type": "update"}\n\n`;
+            for (const clientRes of sseClients) {
+                clientRes.write(broadcastMessage);
+            }
         } catch (error) {
             await client.query('ROLLBACK');
             console.error("Database insert error:", error);
@@ -152,6 +158,13 @@ app.post('/api/data', authenticateAPIKey, async (req, res) => {
     })();
 });
 
+app.listen(PORT, '0.0.0.0', () => {
+    console.log(`Nexstar Backend running at http://localhost:${PORT}`);
+    console.log(`Endpoint for n8n: POST http://localhost:${PORT}/api/data`);
+});      }
+    })();
+});
+
 app.listen(PORT, '0.0.0.0', () => {
     console.log(`Nexstar Backend running at http://localhost:${PORT}`);
     console.log(`Endpoint for n8n: POST http://localhost:${PORT}/api/data`);